Scene of the Crime
by Madin456
Summary: Killua is an assassin who takes lives and Mariko is an information broker who offers him hers because she knows too much. ("Live," he tells the girl. And he's aware of how ironic it sounds, because he himself has just killed someone without a second thought.) — Killua/OC.
**Summary:** AU. Killua is an assassin who takes lives and Mariko is an information broker who offers him hers because she knows too much. ("Live," he tells the girl. And he's aware of how ironic it sounds, because he himself has just killed someone without a second thought.) – KilluaxOC.

 **A/N:** Loosely (very loosely) inspired by Izaya Orihara's character from _Durarara!_ A different take on the information broker life, because all that knowledge can seriously break a person. Oh, and Killua chose to stay as the heir, so lots of death. Seriously.

Originally intended to be 2k words at most. HOW DID THIS STORY BECOME SO LONG.

 **Disclaimer: I do not own** _ **Hunter X Hunter.**_

* * *

Scene of the Crime

* * *

Moonlight is Killua's guide as he maneuvers himself through the silent streets of Yorknew City. The silky, pearl-coloured blanket that falls down like a curtain over the buildings is dim to normal eyes, but for a trained assassin, it illuminates more than enough.

Eighteen-year-old Killua, eyes sharp and claws extended, tracks his prey with ease, completely in his comfort zone of the night. Most of the time, he ends the lives of his targets in their sleep, just coming and going, leaving others to find a corpse in the morning. But occasionally, information leaks or they realize that they're being targeted (because even they themselves are aware of how much of a douche they have been to others), so they run. It's a useless, futile attempt to prolong their inevitable doom—because once a Zoldyck is involved, you're pretty much done for, so there's really no use resisting—but they still try to escape anyway.

The whole thing is tedious, but also kind of exhilarating, Killua admits. Because, hey, what's the harm in having a little fun while on the job?

His target this time is a businessman—it usually is. Tonpa is a rather large man; one of those people who you can tell is wealthy just by looking at them because it's obvious that they have more than enough to eat every day, all dressed up prettily in a suit and tie. He did something to piss off a rival company, something bad enough that caused the other company to send an assassin after him. Killua isn't exactly sure what history these two have with each other, but that isn't his job; his job is simply to kill.

The white-haired boy cuts through streets and freely ignores the traffic lights because when Killua runs, the human eye can hardly keep up and it's not like he'd let himself get hit by a car, anyway. He's inhumanly fast and it's a joke if Tonpa thinks that he can honestly get away; after all, each of his bodyguards are already out of the game.

Killua intercepts the businessman in an alleyway from the opposite side, coming up right in front of him. Facial expressions like the one Tonpa is showing right now are what Killua lives for.

The kill is quick and clean. Killua slices the man's head with one swift movement, a gesture used more to silence Tonpa before he can scream than to complete the job. (Because the screams still haunt Killua sometimes, in the middle of the night when he wakes up in cold sweat. Despite his reputation, the white-haired assassin is still a boy somewhere deep down.)

There is no stalling for time. No toying with his opponent. No unnecessary actions, no time wasted; with a swing of his hand, Killua shakes the blood off his fingers and retracts his claws while Tonpa's head thumps to the floor.

The job is done. The money is secured.

Killua turns to leave when he spots movement in the shadows behind Tonpa's body. He freezes and immediately, his hand is outstretched in front of him again, preparing for an attack.

"Who's there?" His voice is guarded, cautious, sharp alerted eyes darting all around.

The question is met with an agonizing silence. In the background, a single car rushes by, leaving behind a world of smoke and discreetness and an eerie quietness that begins to chip away at his anxiety.

He watches the shadow shift and move forward, into the dim light that illuminates the narrow alleyway. His teal blue orbs scan the person, searching for weapons in their hands or pockets that could pose a threat, when he notices the curve of the person's body and their feminine way of walking.

It's a girl, he confirms when she comes to a stop just inches in front of Tonpa's dead body, a few cautions metres away from the assassin.

"Who are you?" He asks, hoping that she has the right answers; he's really not in the mood to murder an innocent bystander today. "Why are you here?"

She stares at him, brown eyes looking directly into teal ones, unblinking and not the least bit frightened. A breeze blows by, simultaneously brushing through the girl's hair in gentle flutters and spreading the toxic scent of blood from the detached head. Killua gets a strong waft of the iron and he's sure the girl smells it too, but she maintains her silence, not screaming or running like any other person would.

Her eyes flicker down at the body on the floor for a second before returning her attention back to Killua. In a voice that's soft and hollow but crisp and clear at the same time, she whispers two words:

" _Kill me."_

(Killua thinks he must have misheard because no one goes to an assassin to die; they only come to him to get someone _else_ killed so that they can live _longer_.)

The girl's gaze is steady but Killua hears the unintentional quiver in her voice when she speaks and catches the slight twitch of her lips that tells him, _no_ , she doesn't _really_ want to die—not yet.

"Why?" A perfectly reasonable question. The white-haired boy asks this with a frown stretching over his lips. He's already decided: he may be an assassin, a _murderer_ , yes, but he refuses to kill this girl who has seemingly given up on life. In his line of work, he has seen countless people, young and old alike, who have _begged_ to live a few more days, a few more minutes, and would give anything to be in her position. (But, of course, he kills them anyway because that's what he is paid to do.)

He knows that what he does isn't justice of any kind, but usually his targets have done something to, maybe not _deserve_ their deaths, but definitely to be punished. And from what he knows so far, this girl who looks to be around his age hasn't done anything in need of consequences—especially not from a Zoldyck.

"It doesn't matter why," she replies; her voice soft and still not any louder than a whisper. "I want you to kill me." Tiredly, she closes her eyes, as if she really has no more energy to walk on this earth anymore. She is almost pleading. "You just killed that man, Tonpa, right? Doing the same for me should be easy."

There is a pause as the world seems to hold its breath before Killua nods slowly. "Yeah… yeah, you're right." Walking up to her, he makes a slicing gesture with his hands over her neck. His claws are still hidden, but he doesn't need them to create a threatening presence. "I could chop off your head easily, in one swift action, just like our friend Tonpa over there. Your life would be over before you knew it."

The girl looks like she's preparing to breathe her last breath; the assassin circles around the girl before stepping back to face her. "But I won't."

He watches her face turn into one of surprise. If he looks hard enough, there's also a mixture of disappointment and desperateness and something along the lines of regret, but there is also hope hidden somewhere on her facial features.

" _Live,"_ he tells the girl. And he's aware of how ironic it sounds, because he himself has just taken a life without a second thought.

The assassin turns around and walks away, leaving her with that departing message and disappearing back into the shadows of his natural element. The girl's next sentence follows him all the way out of town, ghostly whispers swirling around him in the form of words he can't seem to forget.

" _One day, I'm going to die—and you, Killua, are going to be the one to kill me."_

.

This time, his target is a woman. Pampered and spoiled with an extremely troublesome _Nen_ ability, Killua knows that it is only a matter of time before someone sends him a request to end the life of Neon Nostrade.

As he walks up the stairs of the Nostrade household, Killua speculates on how such a wealthy family can have such weak bodyguards. The men scattered on the floor below him, lying limp, were of no challenge to the aspiring assassin heir at all; he was able to breeze through them, brush them aside with a single flick of his hand, and they could just barely keep up with his speed.

When the white-haired boy reaches the last step of the stairs, he welcomes the feeling of another presence with him in the hallway and rests his arm casually on the glamorously dazzling golden railing, one leg crossed over the other. Maybe he'll actually get a real fight out of this person. He keeps his expression well-guarded, but allows something resembling a smirk to spread over his lips.

"Are you sure you want to do this?" Killua gestures to the pile of corpses on the main floor. "I don't think you want to end up like them." Then, almost as an afterthought, he adds, "And yes, I know that you're there, so you can stop hiding now."

An older man steps out from the shadows. His face is framed with blond hair, crimson red eyes staring directly at Killua from underneath his bangs with the clear intent to kill. In his hands, he holds twin daggers that glisten under the dim lighting of chandeliers hanging on the ceiling. Metal chains are wrapped around his fingers, looping all the way up his arm.

 _Kurta Clan_ , the name comes to Killua after he takes a second to really observe the man's unusual eyes, _so this is the rumoured lone survivor… Kurapika._

"I will protect Neon Nostrade," conviction oozes out of Kurapika's words. If the hard look he is sending Killua's way and his calm exterior isn't evidence enough, then it is the way he speaks with confidence that convinces the assassin that the blond is different from all those other people he faced downstairs. This man is skilled. _Stronger._

But not strong enough.

(Never strong enough. Killua almost feels bad for him; in another life, they could have even been friends, perhaps.)

Killua lunges at his opponent, pushing off the railing behind him, claws aimed to strike at the blond's neck. Speed has always been something the assassin prides himself in, and with the boost of _Nen_ at his feet, it is almost as if he just _appeared_ in front of Kurapika. The bodyguard raises his hands, moving purely on instinct at this point, and manages to block the lethal jab to his throat with only thick, sturdy chains between Killua's sharp nails and his exposed flesh, before twisting around his arm to follow up with a swipe of his blade.

The white-haired boy jumps back immediately, retaliating, and wipes a drop of blood off his left cheek with the back of his hand. The slash is shallow, having barely even grazed him, but Killua scrawls nonetheless, eyes narrowed. He had planned to finish this with one move.

"Interesting use of those chains," the assassin mutters bitterly. Kurapika tucks away his daggers in his belt, looking as if he has already won.

Killua glares at the older man. He doesn't like being looked down upon. This fight _isn't_ over yet; the wound on his cheek isn't even half as painful as a mere papercut, so why—?

Running his hand over his injured skin, Killua puts a finger that is now coated with his blood in his mouth and licks it. A familiar, tingling sensation lingers all over the surface of his tongue, and he barks out a laugh. So that's what it is. "Poison?" He guesses, one eyebrow raised. "You decided to _poison_ me?"

"It will spread all over your body soon enough. You will be fully paralyzed." The blond almost looks smug. "I suggest you turn back now while you can still move and give up on this mission."

In one fluid movement, Killua reaches into his pocket and whips out an electric blue yo-yo. It spirals toward the bodyguard, all fifty kilograms of metal hitting Kurapika straight in the chest before he even registers what is happening. The yo-yo returns to its owner after creating a small hole in the older man's body. Kurapika falls to the floor instantly.

Killua doesn't even spare a glance in his opponent's direction as he walks past the last Kurta survivor into Neon's bedroom. "Poison won't work on me," he calls out to the lifeless body in the hallway, shaking his head at how naïve the blond was. "And now… I guess your clan is officially dead."

Standing over his target's bed, Killua steadies his hand over the girl's neck. It's a wonder how she hasn't woken up yet from all the noise earlier. He raises his arm, prepared to slash down in a quick, clean movement so that her death won't be painful at least, but his hand freezes just inches above the girl's vital point.

He flings the blanket off the bed. Brown hair. Dark eyes. Thin lips. Body shivering, clearly not asleep. "Who are you?" He asks the stranger in Neon Nostrade's bed.

The girl sits up slowly and looks the assassin in the eyes. "Why did you stop, Killua? Why won't you kill me?"

"You…" The white-haired boy recalls that night he chased Tonpa down the streets of Meteor City. This is her: the girl who had begged him to take her life, standing right in front of Tonpa's detached head, completely unaffected by the horrible stench of blood. The girl he had rejected. And yet, he doesn't even know her name. "How did you know that I was going to be here?"

"If I tell you, will you kill me after?"

He should, Killua knows. This girl found out too much about him already, about the Zoldycks and even who his next targets will be. She knows so much about him when he still can't even match her face with a name.

The white-haired boy doesn't understand why he hasn't killed her yet himself—maybe it's reverse psychology: the more she begs him to end her life, the less he wants to do it. She came to him with the strangest proposal he has ever heard and it has messed with his mind; where is the ruthless assassin his big brother Illumi trained for all these years? He's taken numerous lives, and yet, he isn't willing to add this girl to his body count. _(Why?)_

Killua sighs, already knowing that he won't do as the girl asks him despite logic proving otherwise. "Where is Neon Nostrade?" Changing tactics. Focusing on a different subject, hoping to distract himself from his weakness. (Running away. _Coward._ )

The girl stares back at him, unwavering. "I'll tell you, only if you promise to kill me after."

Killua growls, kicking the bed frame in frustration. He's angry—at how much a stranger is affecting him, at how this girl managed to track him. At himself. "Okay, _fine!_ " He needs to punch someone—or kill someone. "Let me finish my mission first, then I'll come back for you, if you really want to die that badly."

He hasn't forgotten his job. (The job always comes first.)

"She's in the bedroom down the hall." The girl looks unbelievably relieved.

A few minutes later, Neon Nostrade is put to eternal sleep, Killua is out the window, and the girl he promised to kill slumps to the ground, still very much alive.

.

"That took you a while, Kil," Illumi is there to greet the white-haired assassin when he returns from his mission. "I didn't think it would be that difficult for you to deal with the Nostrade family."

Killua looks away, trying his best to sound nonchalant. "I got caught up in something for a few minutes. Nothing important."

The older sibling is quiet for a moment, dark eyes observing the heir with an unreadable expression on his face. It's a long moment before he finally speaks. "Well, you got the job done, so it's fine. There's been another request for you while you were away." Illumi reaches into his pocket and flicks a piece of paper in his brother's direction.

There is a name, a picture, and an address on the sheet. Mariko Sasaki [1]. 36 Bayloke Street, Yorknew City [2]. Killua doesn't recognize the name or the address, but he can't deny the fact that he _has_ seen the person in the photo before—just tonight, in fact. He curses.

Perhaps she will get her wish after all.

.

The best way to describe Mariko Sasaki's room, Killua thinks, is an organized mess.

Although the bed on the left side of the room is made nicely, blankets folded and bed sheets tucked in at the corners, there are about a dozen pillows scattered all over it. On the opposing walls, three desks are lined up in a row. Four computers share the surface of the first two desks, placed in front of a rolling chair, while the remaining table is split into two sections: one side for an abundance of notebooks, the other side occupied by a cluster of cellphones.

When Killua enters the girl's bedroom on the second floor via the window that he pried open, he almost knocks over one of the monitors while launching himself into the building. He's glad that he didn't end up breaking anything though, because if Mariko is anything like his brother Milluki, she might have gone on a rampage if she sees her equipment damaged.

(Because knocking and simply waiting for someone to answer the front door would have been too easy and civilized for the white-haired boy. One unique perk of being an assassin is that he can make a dramatic entrance whenever he wants.)

There is a _click_ at the bedroom door and Killua turns around to find himself face-to-face with his target.

"Are you finally here to kill me?"

There is no indication in her voice that she's at all surprised to see him in her room uninvited.

 _No_ , Killua answers silently. He never had any intention of killing her.

"What are all these computers for?" He asks instead.

The girl raises an eyebrow. "So we're going to do the interrogation-before-death thing, then? Alright," she sighs. She's not going to die tonight, she knows. _She knows_. "The computers are what I use for collecting information—um, _illegal_ information, you could say. Sometimes, this includes hacking into large business corporations, depending on the request. Tracking a person's online history, sending out viruses if necessary—that's all done on these computers here."

"And you're being paid to do this?" Killua wonders what kind of job she has.

"Yeah," the girl sucks in a breath, "I work as… an information broker. People come to me for, well, all kinds of things. Usually, it's for blackmail. Actually, it's _always_ for blackmail. They want me to dig up some dirty secret their rival company has, or they're just cautious and want to be prepared with hidden information at their disposal—that whole 'knowledge is power' mindset, you know. As long as they're willing to pay, I'll do basically anything they ask, and things have been going pretty well so far, considering the fact that I haven't been caught yet." She gives Killua a look that challenges him to comment on her morals, knowing that if he does, he'd just be a hypocrite.

Killua stays quiet, fully aware that he has no right to lecture her about this; after all, his line of work is pretty much the same: if the compensation matches the request, he will kill anyone he needs to. ( _Except her_ , a voice in his head whispers, to which he promptly replies with, _Shut up._ )

She seems satisfied with his silence and continues, "It's hard, though. Having all this data swirling around my head every day, all these things I'm not supposed to know… I don't think I can take it anymore. Some of the things I've learned, Killua, you won't believe what people would do just to protect their own pride. The amount of innocent people who are affected by the poor decisions of big companies, like the one Tonpa worked for. It's _disgusting_.

"And then, other people—angry people—started realizing that the information circling around had to come from somewhere. I knew that it was only a matter of time before they traced it back to me, and at that point, I figured I was dead, anyway. So I did some digging around. It took me to while to find, but I learned about a group of people who would kill anyone you wanted, as long as they received their payment." She gives Killua a smile that he can't quite read. "They were a group of assassins, a family business—the Zoldycks."

From here, the white-haired boy could guess what went through her mind after that. She figured that since she was going to die either way, she wanted to do it on her own accord, before one of her angry clients got to her.

But there is another option, that doesn't involve death. Because, in essence, her work is similar to Milluki's and Killua has always wanted to be able to gain information without having to worry about repaying a debt to his older pig of a brother.

"Well, what if I find you a new job… Mariko?"

The girl frowns. If she's surprised that he knows her first name, she doesn't show it. "The only thing I'm good at is computers."

The assassin waves it off dismissively. "That's fine. You'll be gathering intel and hacking into security systems, if necessary, and any other geeky tech stuff that might be required."

Mariko raises an eyebrow at the word _geeky_ , but seems to consider the offer. "Who would I be working for?"

At this, Killua grins. "Me."

.

The two of them make their way to Kukuroo Mountain, hand in hand, as newly formed partners and unexpected friends. Illumi is furious when he sees Killua's target still alive—when he sees Killua _with_ his target—and demands for an explanation, to which the white-haired boy calmly answers, "She'll be helping me from now on." He tries to step around his brother, but Illumi firmly blocks the path.

"This wasn't your job, _Kil_." Dark eyes stare down teal ones, a menacing aura flickering around them dangerously. "How are you going to inform your employer of this _failure_?"

"I'll kill him," Killua's voice is steady, matter-of-fact. The look he gives Illumi is challenging and he squeezes Mariko's hand reassuringly.

The next day, the man who wanted the information broker dead receives a surprise visit from the Zoldyck heir and a few seconds later, he slumps to the ground, lifeless.

After that, their true partnership begins. They start off with another request: the subject this time is a large corporate owner who goes by the name of Meruem. Recently, there are stories that he has been abusing his employees, and in fact, it's one of the victims who sought out Killua for help.

"Be careful," Mariko cautions him before he leaves, "This Meruem guy is said to have some pretty tough bodyguards."

Killua nods his head to where the girl's monitor displays footage from all security cameras in the corporate building. "I'll be counting on you for that."

And then he's gone. Mariko takes a second to breathe; this will be her first assassination mission, and while she isn't actually out in the field doing the physical work, she knows that she's still part of the battle. The computer she left behind at her old house has been upgraded, which basically means that Killua waltzed into Milluki's room one day, picked up one of his many desktops, and brought it back for her to use, brushing aside any concerns with, _"He probably won't even notice it's gone."_

On the screen now, she can see that Killua has successfully infiltrated the building. She gives him directions, which he receives through the earpiece that's connected to Mariko's speakers—something else he took from Milluki, most likely. Her voice guides him directly to the first room on the top floor, and if the door marked "Meruem" isn't enough to convince him that he's in the right place, there are also three menacing bodyguards stationed in position in front of the door.

They sense him before he even has the chance to act. The large man with tanned skin standing closest to him sniffs the air, as if he can pick up the scent of an intruder. This alerts the other two, and the three of them all advance toward him together. They're strong, Killua can tell, stronger than Kurapika or anyone else he's encountered. For a second, he doubts his skills and contemplates running away, but then the earpiece buzzes to life.

"Get ready, Killua," he hears Mariko clearly despite the static, and it's all the motivation and reassurance he needs; he jumps out from around the corner, sparks flashing around him.

He hurls a lightning bolt in their direction and the bodyguards scatter, jumping aside to avoid the attack. However, the hallway is narrow, and so they cannot fully avoid the impact, but it's not enough, not even close, because they're distracted at best and hardly even phased. The one with eyes resembling a cat's lunges forward, aiming at Killua's right arm, and manages to make contact. Killua cries out in pain but the veil of electricity around him protects him from most of the damage.

In a matter of seconds, while the assassin checks to make sure his arm isn't broken, the three bodyguards have surrounded him. His eyes narrow as he begins to walk back and forth, in a circle, until after images of himself appears. As his opponents are busy figuring out which one is the real thing, Killua plans to take them out one by one. Unfortunately, he should've known it wouldn't be that easy.

"Youpi!" the blond calls out. The tanned man from before nods on his cue and sniffs again, pinpointing the assassin with ease, following only his sense of smell. He raises a fist, charging _Nen_ to his hand, and Killua's brain goes to overdrive as he panics and desperately tries to think of a way to avoid the punch.

He can't. The other two bodyguards are blocking him from both sides and the space isn't wide enough for him to run anywhere. It's too late, anyway—the blow hits him in full force a minute later and he's knocked back so hard that parts of the wall behind him chips off. Groaning, he lies there on the ground, head spinning. There are too many of them, he is thoroughly outnumbered and overpowered; he might be able to take on one of them, but three? The outcome is already evident.

Killua hears a gasp from the earpiece as he struggles to get back on his feet. "Oh my god, Killua, are you alright? You should get out of there! We can try again next time—they're just too strong—you don't have to force yourself—"

The white-haired boy smiles, despite everything, at Mariko's flustered words. He thinks of how, if he abandons this mission now, he will only be regarded as a _failure_ again when Illumi finds out, and how there _has_ to be a way to defeat these inhumanly strong bodyguards, because he's the _Zoldyck heir_ and he didn't go through all that training these past eighteen years just to be _defeated_ here. And what has he gained over the years? Speed, yes, and his very own _Nen_ ability, but those aren't nearly as important compared to— _tactics_. Strategy. If he is outnumbered and overpowered, then he will _outsmart_ them.

Killua steadies himself against the wall and tests out his muscles, moving his arms and legs to make sure that they're still functioning. This is nothing compared to some of his past experiences.

He inhales. "Mariko," he whispers at a volume he knows his opponents won't be able to hear, "can you hack into the security system of the building and turn off the power?" Because how could he have forgotten? The girl has the entire office at her fingertips and she only has to type a few strokes on her keyboard to completely take over anything technology related.

Mariko slumps in relief at the sound of her partner's voice. "I'm on it," she replies. Sounds of tapping and fingertips hitting the keyboard fill the static between them, and exactly two minutes later, Meruem's company is experiencing a black-out.

The assassin doesn't waste any time. The instant they are surrounded by darkness, he knows that he has gained the advantage; while everyone else is struggling to see in the dark, Killua is already accustomed to carrying out missions at night. He pierces a clawed hand through Youpi first, aware that if the moment of surprise passes, the man would attack him again, solely following his keen sense of smell. Killua is satisfied to hear a _thump_ as Youpi falls to the floor, his companions crying out, panicked.

His next target is the person who happens to be the closest to him: the slender, blond man to his right. It isn't long before he joins Youpi as a corpse on the ground.

The remaining bodyguard is furious and, filled with rage at the death of her comrades, she lunges forward blindly. The sudden attack throws Killua off guard for a second before he strikes out at her in return, claws aimed for her throat. It takes him a while but eventually his hand connects with her skin and all three guards have been defeated. He's surprised at how long his last opponent, the cat-eyed woman, was able to last, blocking his advances on pure instinct alone.

The three of them had been strong. Some of the strongest opponents he's faced so far. But even though he's panting from the fight and his damaged arm is stinging like crazy, Killua isn't done yet—he still has to take out his target.

He can feel Meruem's dark aura from out in the hallway; the killing intent is so fierce that it makes Killua shiver. There is definitely no way that the assassin can sneak up on the cooperate owner now that it's obvious Meruem knows about an intruder in the building—the only question is why he hasn't gone to check on his guards or made any indication of preparing for a fight.

The sight Killua sees when he flings open the office door open is not quite what he expected. A man, presumably Meruem himself if the pictures Killua has seen are accurate, sits behind a large wooden desk. In front of him is a girl with hair a similar shade to Killua's pulled back into two pigtails by large, yellow hair ties and thick, thick eyebrows. She turns in the direction of the doorway at the sound of someone entering, but by the way she blinks, it's as if she doesn't see anything at all.

In between Meruem and the girl—a client, perhaps?—is what appears to be a Gungi board set up on the office table.

"Who are you?" The businessman demands. His _Nen_ flares around the room threateningly and it's one of the coldest feelings Killua has ever been exposed to, but he remains mute, eyes never leaving his target. He is injured and already worn out and his instincts are screaming at him to run. He doesn't. Slowly, he shuts the door behind him and takes a step into the room. Tension holds still in the air.

The girl reaches out and picks up one of the black Gungi pieces. She's relaxed, seemingly unaware of the silent battle between the two men. The piece in her hand is the Knight, and with a flick of her wrist, she places it down on the board, in the space directly in front of the opposing white King.

It's a strange move. If anything, it seems like a defensive action which doesn't make sense because a black Knight can't possibly act as a shield for the white King. Meruem's eyes flicker down at the board for a second, trying to decipher the girl's decision.

Killua chooses this moment to strike. He moves quickly, materializing in front of his target, and thrusts a hand forward, sharp nails fully extended. He makes contact and pulls back. What he stabs, however, isn't Meruem.

There is a second of complete silence as the world pauses for the tragedy before the corporate owner lets out an ear-piercing scream. _"Komugi!"_ The girl falls on top of the Gungi board, staining the pieces in red. Meruem bends over her body, clasping her hands in his as he tries desperately to treat the wound. (She can't be saved though, Killua thinks grimly, because when he lunged forward, he had been aiming for the heart.)

Komugi glances up to look at her partner and already, she can feel her energy fading. "I'm glad I got to be your Knight in my final moments, my King," She heaves her final breath, coughing up blood. The girl forces a smile as her eyelids begin to close. "I end my turn."

Meruem drops his head in despair. His eyes tear up and the world blurs over as he watches the Gungi player's body go limp in front of him. She's gone and he's still here, and he doesn't deserve to be here, he knows, doesn't deserve to be _alive_ —but he is. Even though he treats his employees poorly and forced Komugi to compete in games with him on the treat that he will fire her if she disobeys, she still gave up her life to save his.

He never asked her to be his Knight. _He never wanted to be King._

Killua attacks again and this time, there is no Komugi to block the blow. Meruem feels his skin being torn apart, feels the world getting hazy, but there is a distinct lack of pain. Meruem is dying but he doesn't feel anything except the sorrow he has for the girl in his arms.

He kisses Komugi's forehead and his hands slip into hers easily. In their next life, if such a thing exists, he prays that he'll get to meet her again, even if he is reborn as an ant and has to somehow kill the entire human race just to find her. And then, finally, he closes his eyes.

The assassin stands, watching the devastating scene. He's killed many, many people before, but he has never ended a life by accident. No one has ever sacrificed themselves for a target like Komugi had done for Meruem just moments ago. It's just another death, the white-haired boy tells himself, just another stilled heart out of who knows how many he's witnessed, but he'd be lying if he says the Gungi player's action doesn't affect him.

"It's okay," Mariko's voice vibrates in his ear, quivering a little bit, but soft and reassuring all the same. He almost forgot that she's still there. "It's _okay_ , Killua. Come back home."

He inhales a shaky breath and nods. It's weird how he clings to her words like a lifeline and how he lets them soothe him, wash over him, and how, in the end, _it's okay_ because—he believes her.

Killua returns home safely to Mariko, they exchange high-fives, and then it's on to the next mission.

.

After almost a year of working with the Zoldycks, Mariko Sasaki's name is still circling around various rumours in the darker parts of businesses. She had created quite a name for herself prior to her first meeting with Killua and over the past few months, there have still been requests coming in for her to retrieve documents from security systems or hack into corporate databases. Normally, she declines these jobs because she is already fully occupied with assassination work, but this particular request manages to catch her attention.

"Have you heard of the Zodiacs?" She asks her partner, motioning to the email on her computer screen so that the white-haired boy can take a look.

He raises an eyebrow and leans in to scan the message. "You mean the ones in charge of the Hunters Association? Why would they be contacting you?"

She shrugs because, really, she doesn't know. The email mentions Pariston Hill, a triple star Hunter who goes by the codename Rat. The image of him provided displays a blond man with brown eyes and a too-sweet, radiating smile that seems to sparkle off the page. He is dressed formally in a suit and tie and, partially due to the accusing tone in the email along with her own speculations, there's just _something_ about this man that doesn't sit well with Mariko.

What surprises her the most, however, is the fact that Pariston, the current Vice Chairman of the Association, is being targeted by his superior, the Chairman, Cheadle Yorkshire.

"It says here," Killua quickly looks over the request, "that Cheadle wants you to hack into Pariston's computer to uncover everything he's done over the past few months."

The demand itself is perfectly normal for the kinds of jobs she took on when she was still an information broker, but the girl frowns now. Hacking into a highly protected account undiscovered is not an easy task and she has no doubt that Pariston's computer will have a stronger security system than the average person's. She ponders over the situation. "It'd be a lot easier if I could connect my laptop directly to Pariston's so I can transfer the data and look more into it afterwards…" But, realistically, what are the chances of that happening?

Mariko finds it extremely tempting to refuse the offer. She'd have to go through a lot of trouble just to get in touch with the Vice Chairman's computer and if she were to get caught, she'd be completely defenseless. Not to mention that he is a _triple star hunter_ , the highest title anyone can obtain.

On the other hand, though, Cheadle, as the Chairman, currently holds a position that even surpasses Pariston's. Angering someone of such powerful authority will also result in negative consequences. And the reward of over one million Jenny is admittedly doing a good job of bribing her.

None of her options seem particularly promising at the moment.

Beside her, Killua is watching her intensely. "You're doing it again," he says, frowning.

Mariko blinks. "Doing what?"

"Retreating into your thoughts. Trying to take everything on by yourself." The assassin rests a hand gently on the girl's shoulder—because, _yes_ , even though his very same hands have killed, they are still capable of compassion. "You're not alone anymore, remember?" Something resembling a smirk flitters across his lips. "You work for me now. Any decision you make has to be approved first; otherwise, I might just fire you," he teases playfully, adding a light tone to the otherwise serious mood.

The girl's shoulders relax visibly and she feigns hurt. "Fire _me_? But I'm your best employee!"

"My _only_ employee."

Mariko laughs and it's like all the stress has left her body at once. Then, back to serious, she says, "I think I'm going to go." She inhales, scanning the request once more, nodding. "I'm going to take the job."

Killua leans back, hands in his pockets. "Alright, then I'm coming with you." Like it's the most natural thing in the world.

"No, you don't have to—"

The assassin waves off her protests dismissively. "I _want_ to."

"But… why?" This job doesn't require any physical fighting, much less any killing, and Mariko is pretty sure that hacking isn't one of her partner's strengths, no matter how talented of an individual he is. Plus, she's confident in her abilities, even if she has to get into the Vice Chairman's tightly secured system. It might take longer than usual, but she's sure that she can do it.

"I'll watch your back. You're going to be in a building full of skilled Hunters and you'll be vulnerable when you're focusing on all the tech stuff." He smirks. "And, well, you _are_ my best employee."

Mariko looks at the white-haired boy in front of her and almost feels like crying because, really, what did she do to deserve a friend like Killua? There's an urge to hug him—and then there's an even stronger urge to _kiss_ him. She doesn't do either of those.

And she doesn't say _thank you_ either but the message is there, echoing loudly off the silence in the room.

Killua smiles.

.

It turns out that entering the Hunter Association building is easier than expected.

When the receptionist asks for identification, Mariko hands her some cards she forged. There is a match to their fake names—Chieko and Kane for Mariko and Killua respectively—in the database because the information broker had hacked the system the day before and added in their entries.

The worker glances up at them and smiles pleasantly. "You guys are a little early for your meeting with Pariston Hill today, but feel free to wait for him in his room." She gestures to their left. "It's just down the hall over there. He should be arriving in a few minutes."

They thank her and make their way to the indicated room, chatting idly about nothing in particular. It's all pretend, anyway; just a show to put on for the security cameras that are undoubtedly monitoring the actions of everyone in the building. Of course, disabling the cameras in such a well-protected place would have been a challenge, but given some time, Mariko would have been able to do it. The only problem is that having even just one camera go blank would draw attention to them for sure.

Settling down in Pariston's room, the girl looks around and takes in the space. In the middle is a rectangular table with a laptop attached to numerous cords sitting at the far end, a small plant off to the side, and a few bookshelves filled with more miscellaneous things than actual books—but none of that matters, really. Her eyes flicker to one corner of the room, where a single camera is stationed to see a full view of the room.

She takes a seat right beside the laptop so that she is facing the camera and motions Killua to join her. Pulling out her own computer, she turns it on and after a few seconds, gasps in surprise. "Oh, it's out of battery." She turns to her partner and tilts the device just enough for him to see the perfectly lit screen. "Do you think it'll be okay if I borrow Pariston's charger…?"

Killua seems to consider it before shrugging and playing along with her scheme. "It should be fine. I'm sure he'll understand if we explain it to him."

Mariko unplugs a cord and attaches it to her laptop, but it's not the charger. A window pops up asking for a password in order to further access the information and the girl spends the next few minutes trying all kinds of different codes, typing things in rapid successions, in attempt to gain entry to the triple star Hunter's data. She can hear the time ticking away on the obnoxiously loud clock behind her as she grits her teeth, wondering how long it'll be before Pariston returns.

She feels a hand on her shoulder and pauses for a second to look up at Killua. His eyes are telling her to calm down, to believe in her own abilities, and she realizes that she's far too anxious right now to be able to focus properly. Drawing in a deep breath, she tries again.

The clock is still ticking rhythmically but Mariko doesn't hear it anymore. She's immersed in the task, going through all the possibilities one by one. And then—

—she's in.

Grinning, the girl reads the new text on the screen.

ARE YOU SURE YOU WANT TO TRANSFER THESE FILES?

She clicks YES and leans back, watching the documents move from Pariston's laptop to her own.

Now, they wait.

.

With a coffee in one hand, Pariston Hill steps through the sliding doors of the Hunter Association's building and greets the receptionist with a smile and a nod.

"Oh, Pariston!" the woman calls out to him just as he's about to head deeper into the building. "Your clients are waiting for you in your room. I told them you would be returning shortly."

The smile slides off the blond's face as confusion takes over his features. "Clients ?"

The receptionist nods. "A boy and a girl. They said their names were Chieko and Kane and that they had a meeting with you."

Pariston thinks back to his schedule for the day and doesn't remember anything about setting up a meeting. Did he forget? No, impossible, Beans recites his activities to him every morning in that annoyingly squeaky voice of his like it's the bible; there's no way that he would have zero recollection of it at all.

"Um," Pariston blinks back into the present when the receptionist continues, "if you weren't planning to meet them, I can get someone to ask them to leave." She tries to keep her tone even, but talking to the pro Hunter has always made her nervous and she secretly wishes that she would be relieved of his presence soon.

"No, no; it's alright," the man takes a sip of his coffee, his usual smile back on his face when he sets the cup down. "I'll take care of it myself. I was just heading to the room, anyway."

He is sent off with a polite bow and he walks down the hallway humming softly. It seems like things are going to get interesting.

The sight Pariston sees when he arrives at the doorway of his office is two kids hunched over a laptop screen, and—is that a cord connecting to his own laptop?

With silent footsteps and a concealed presence, the triple star hunter walks up behind his unsuspecting guests and unleashes a blast of aura all at once, amused to see the kids jump at the overwhelming change in atmosphere.

He spares a glance at the glowing screen that currently shows his files being transferred at sixty percent. His eyes narrow but the corners of his lips turn up into a threatening smile. "Please excuse my poor punctuality… I wasn't aware that I had a meeting planned for today. Now, how can I be of assistance to you… Chieko and Kane, was it?"

The two of them go wide-eyed and Pariston chuckles quietly to himself. They're so _cute_. It's almost a pity he has to kill them now that they've attempted to snoop through his belongings. Even the potential that they've seen something important is unacceptable.

The white-haired boy looks like he's about to say something and make up some bullshit excuse about their actions but Pariston cuts him off before a word leaves his mouth.

"By the way," the man drawls, "did you know that it's protocol to have anyone who enters the Hunter Association building vaccinated, just in case they bring in a disease with them?" Pariston walks over to the bookshelf and picks up a clear bottle containing purple liquid that seems to resemble perfume. He coats a needle with the substance and twirls in between his fingers casually. "The rules are very strict, after all. Luckily for you, I happen to have a sample of the vaccine right here in case anyone manages to bypass the system."

The boy and girl have no idea what he's talking about, but they share a single thought when they exchange looks: screw the job; _they need to get out of here._

Pariston looks up from the needle in his hand and locks eyes with his guests. In the next second, the Hunter has crossed the distance between them and appears behind them. He's _fast_ , already taking action before the assassin and information broker can even take a single step, and he stabs the tip of the needle into their arms. Pariston withdraws and jumps back just in time to avoid a swing from the white-haired boy.

Leaning against the desk, one leg crossing over the other, Pariston allows his aura to diminish. "Now, I believe this meeting is over," he's still smiling but his eyes narrow, indicating that if they still wish to challenge him, he _will_ fight. "You will leave your laptop here and—"

Before he has a chance to finish, a blur of light flashes in front of him and his eyes are just barely able to follow the white-haired boy as he grabs his partner and jumps out the window. The blond blinks, now alone in the room. _Interesting_.

He doesn't bother chasing after them. It's not like they have much longer to live, anyway.

As he tidies up the mess left behind by the whirlwind that Killua created during his escape, Pariston's expression turns serious, looking even more dangerous than before. Now, on to more important matters. Who could have sent those kids after him? He taps him chin in concentration. It's doubtful that they are working alone considering the fact that he's never seen either of them before, so they must have been hired to do the job. Pariston has a lot of enemies, many of whom would love to see him dead, but this had not been an assassination mission.

He thinks, perhaps, that this issue is a lot closer to home.

The blond grins. He's going to have a _long_ talk with Cheadle the next time he sees his fellow Zodiac member.

.

Killua is still carrying Mariko when he slows to a jog a decent distance away from the Hunter Association building. He inhales a deep breath, finally away from that tense, suffocating atmosphere back in Pariston's room. The man's aura had been insanely strong, choking them in a hold, and Killua's never experienced being unable to move just by being exposed to a person's _Nen_ before.

They're safe now but the assassin's grip on his partner only tightens because—they could have _died_.

"Are you okay?" He asks, but he doesn't even need to hear Mariko's reply when he sees blood trickling out of her mouth as she coughs so violently that her entire body convulses to know that no, she is _not_ okay.

"P-poison," the girl struggles to speak. "He poisoned the needle."

 _No._

Killua instantly stops running. He can feel his hands starting to shake and he's _so_ _angry_ with himself because he didn't feel anything at the time so he had pushed the whole thing aside, focusing solely on their escape. The story about vaccinations had been complete bullshit. And despite being an information broker, Mariko is still just a normal human. And normal humans aren't immune to poison.

"An—an antidote. We need to find an antidote," Killua looks around frantically, but there's nothing he can use to help the girl in his arms because the only one who can reverse this is Pariston and Pariston is all the way back in that building Killua fled from with too-tight security—and they're _running out of time_. He doesn't particularly _want_ to face the blond hunter again either, if he's being honest, but Mariko is _dying_ and he needs to _save her._

"Don't go," his partner rasps. The assassin glances down at her and somehow, even with poison inside her body, she is still able to figure out what he's thinking without him having to voice the thoughts. "You do it too, you know? Retreating into your head and letting the panic take over. The answer this time is simple; do what you have to do."

It takes all of Mariko's strength to lift her head up at Killua. She feels the poison spreading throughout her body, her limbs going numb one by one. Despite everything, she laughs weakly. "I knew I would die because of a job as an information broker… but I'm glad that I got to experience being an assassin's partner too. Thank you for hiring me." Mariko smiles sincerely, but just the simple upward turn of her lips brings an aching sensation to her muscles. "Kill me, Killua," her voice is barely a whisper, but it's enough. She knows that the Zoldyck heard her.

Killua's eyebrows furrow in sadness and there are tears flowing silently down his cheeks. He has to bite his lip to stop himself from sobbing. The situation reminds him of the first time she asked him to kill her, back in that alleyway in Yorknew City where he ended Tonpa's life, and he wishes—he wishes _so badly_ —that he could decline her request now like how he did before.

But death doesn't take no as an answer, and certainly not twice. He knows that better than anyone.

" _Kill me,"_ the girl repeats more urgently, begging now, just wanting the pain to end. _"Please."_

And this time, he does.

* * *

 **A/N:** So… I guess I killed off Tonpa, Kurapika, Neon, Youpi, Pouf, Pitou, Mereum, and Komugi. And my OC. Wow, that's a lot of people now that I've listed them out. I'm sorry. (Not really.)

I don't think I truly understood the phrase "the story writes itself" until now… Mariko and Killua were never supposed to be friends, much less partners or implied love interests (though I killed off Mariko before _that_ storyline could progress, oops) but that's what the story wanted and that's what we have now. I am but a slave to the plot.

Let me know if you caught any of the subtle canon references! I think there were only like two or something haha I tried.

The footnotes:

[1] Mariko's name means "knowledge", which I think relates to her being an information broker well. Her last name, Sasaki, is random.

[2] Bayloke is the name of one of the hotels in Yorknew City, according to the HxH wiki page, so I just used that as a street name.

I still can't believe how long this story turned out to be.

~Madin456.


End file.
